Revised Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (Part 3) (First Revision) which is identical with ISO 9177-3 : 2022 ‘Mechanical pencils for technical drawings - Part 3: Black leads - Bending strengths of HB leads’, issued by International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Educational Instruments and Equipment Sectional Committee and approval of the Production and General Engineering Division Council.

This standard was originally published in 1984. This revision has been taken to align it with the latest version of ISO 9177-3: 2022. This standard specifies bending strengths and a test method for black leads of HB hardness degree used for mechanical pencils for technical drawings.

The major changes in this revision are as follows:

a) The first element of the title has been revised for consistency with ISO 9177-1, with the addition of “for technical drawings”;

b) Clause 2 has been updated;

c) A bibliography has been added; and

d) Minor editorial changes.